1. Field of the Invention
The present invention is directed to a digitally programmable radio including a receiver and a transmitter that can be digitally reconfigured to operate over a broad radio band and with different signal formats and, more particularly, to a system that provides dynamically programmable and configurable channels using digital channel components to maximize reconfiguration flexibility for use in navigation systems such as Instrument Landing Systems (ILS). Although ILS is normally referred to in this application, other navigation systems are also similar and may be easily developed by one skilled in the art.
2. Description of the Background Art
Many commercial and military applications require multiple communication, navigation, and identification (CNI) or telemetry radio frequency (RF) functions to be performed at a single location. The conventional method for servicing multiple CNI functions is to use independent radio frequency (RF) receivers, each covering a specific portion of the RF band corresponding to a specific CNI function.
Various applications require greater than 10 different types of CNI radios. At one extreme, communication, navigation and identification (CNI) multi-radio suites are comprised of an independent and different type radio channels for each radio functional thread. At the other extreme, integrated programmable radio systems, now in development, cross-couple various elements of multiple channels, which results in a highly complex system of tightly coupled resources.
Both approaches, including hybrids of the two approaches, have advantages as well as major disadvantages. For example, when redundancy is required the independent channel systems must have separate and complete backup radios for all important critical systems, such as instrument landing systems (ILS), which can be very costly. Further, size and weight of the system precludes implementation of multiple CNI functions in many manpack and vehicular applications. The cross-coupled systems are extremely difficult to maintain because fault isolation is difficult due to the complexity of signal distribution and switching; discourage addition of new or modified functions due to a high cost of system redesign and recertification.
A programmable common digital radio is needed which provides an integrated solution for many different types of multi-function CNI suites provided in a small size, with a light weight at a low cost, without the disadvantages suffered by other architectures as described above.